Westendorp is a Dutch surname. Notable people with the surname include:
Betsy Westendorp-Osieck (1880–1968), Dutch painter Carlos Westendorp (1937–2026), Spanish diplomat and politician of Dutch descent Fiep Westendorp (1916–2004), Dutch illustrator Gérard Daniel Westendorp (1813–1869), Belgian physician and botanist Juvat Westendorp (born 1989), Dutch dancer, choreographer and actor Menno Westendorp (born 1969), Dutch cinematographer Sven Westendorp (1969–2011), Dutch criminal, graffiti artist and designer
See also Westendorp v R, a Supreme Court of Canada case.